In addition to storing images internally, modern imaging systems need to be able to transfer images to various types of remote devices via a communications network. To successfully transfer images, the relevant networking features of the imager must be compatible with the networking features of the destination remote device. In particular, the imager must place the data to be transferred in a format which can be handled by the destination remote device. An attempt to accomplish the foregoing is the adoption of the DICOM (Digital Imaging and Communications in Medicine) standards, which specify the conformance requirements for the relevant networking features. The DICOM standards are intended for use in communicating medical digital images among printers, workstations, acquisition modules (such as an ultrasound imaging system) and file servers. The acquisition module is programmed to transfer data in a format which complies with the DICOM standards, while the receiving device is programmed to receive data which has been formatted in compliance with those same DICOM standards.
The DICOM system is designed to facilitate the communication of digital images of different types, e.g., X-ray, computerized tomography, magnetic resonance and ultrasound imaging. In an ultrasound imager having conventional DICOM capability, three local real-world activities occur: Image Send, Image Print and Remote Verification. Image Send and Image Print can be done in either automatic or manual mode. Verification of remote DICOM devices configured on the ultrasound imager is performed when the imager is powered up or when requested by the system operator.
All DICOM activities are handled in a queued manner by application software running on a host computer incorporated in the imager. In one type of ultrasound imager, the user can select any image in cine memory to be sent in DICOM format via a local area network (LAN) to a remote device having DICOM capability. The host computer of the ultrasound imaging system is programmed with DICOM system software which facilitates transmission of image frames from the cine memory to the remote DICOM device via the host computer hard disk and the LAN.
In the conventional ultrasound imager, Image Send can be used in automatic or manual mode, depending on the user configuration. When automatic mode is configured, console keys are used to capture the image and to store it on the hard disk. The request is queued to a DICOM queue manager (preferably implemented in software), which requests an association with the destination remote device. After the association with the remote device has been opened, the queue manager “pushes” the image to the remote device without user intervention. The transfer is done in the background while scanning or other operator activities continue. In manual mode, the captured images are archived on the hard disk or on a MOD during the exam(s). Upon completion of the exam(s) the images are tagged using an archive menu and queued to any of the network devices that have been configured on the imager. The images are sent sequentially in the background while scanning or other operator activities proceed. Image Print works much the same way as Image Send, in both automatic and manual modes, the only difference being that the destination device is a printer.
In addition to the digitized image (i.e., pixel data), the DICOM object transferred from the ultrasound imager also includes an image header. The image header includes an identifier which uniquely identifies the study that the transferred image is part of. DICOM has defined a unique number for each and every study. Every DICOM image in a study must have this number attached to it. This unique identifier defines all images associated with the identified study. The image header also includes attribute information extracted from a pre-stored configuration file. For example, the attribute information may include patient attributes (e.g., patient name and patient identification number), exam attributes (e.g., exam description and exam date), series attributes (e.g., modality type and series date), and image attributes (e.g., image type and numbers of rows and columns).
The DICOM images constructed by an imaging system can be sent over a network to a viewing station or to a picture archiving and communications system (PACS) having a viewing station. The images are sent via an Ethernet port incorporated on the imaging system. It is also known to send reports from the imaging system to the viewing station via a serial port, also incorporated on the imaging system. Typically the serial port transmits and receives data in accordance with the RS232 protocol.
The off-line view station can be used to display the images and reports received from the imaging system. However, one problem is that, while DICOM defines the standard for transmitting images and data along with providing the necessary information to link all associated information with a study, it does not define any RS232 protocols for transmitting report data. Therefore, there is no standard that demonstrates the ability to link RS232 data with a DICOM study. Many companies have developed their own mechanism for transmitting report data via an RS232 interface. Also there are companies that have developed software to receive this RS232 data on a personal computer. The problem is that the companies that have developed the reporting software on the receiving personal computer cannot guarantee that the report data received is related to the DICOM images received. In other words, there is no way to accurately link the report data to a study (comprising a series of images) on a view station or PACS. Some companies have created a proprietary method of linking images and report data that is based on time and video capture, thereby losing much of the associated study information.
In one known ultrasound imaging system, whenever a study is begun, a unique Study Identifier is generated for that study. DICOM refers to this as the Study Instance UID. Each image that is taken during that study will have the Study Instance UID placed in the image header. Also found in that same image header are: Patient Name, Patient ID, Accession Number (a RIS-generated number which identifies the order for the study), Study Date, Study Time, and Patient's Date of Birth. During the exam, the sonographer may make measurements and comments about one or a group of images. The sonographer may also produce information or make comments about the entire exam. This information is placed on the report screen of the scanner. In the known ultrasound imaging system, the sonographer can take a screen shot of the report screen and send it as a DICOM image to the view station. Although that image has a header, that header does not contain the measurement data and other report data. That data only appears on the view station display screen as an image or screen shot. The receiving computer is unable to recognize the measurement data and other report data which are embedded in the image. Thus, the receiving computer is unable to automatically interpret and process the measurement data. For example, several companies sell software applications which receive the measurement data, input it automatically into a database, where it can be retrieved for use in generating reports, re-calculating the data, etc.
There is a need for a method and an apparatus that would allow report data to be sent out the serial port of an imaging system to a view station in such a way that the report data can be automatically linked to the images (sent out via a different port) with which the report data is associated.